TUCSON, Arizona — Jared Loughner, the gunman accused of trying to assassinate a US congresswoman and killing six people in Tucson, pleaded not guilty to all 49 new charges against him Wednesday.

He entered the pleas in his first court appearance in Tucson itself, after prosecutors announced new indictments against him last week following the January 8 Arizona shooting spree.

Sitting quietly, the 22-year-old listened as the 49 counts including multiple murder charges were read to him. "Jared Lee Loughner, is that your true name?" a court official asked.

"Yes, it is" Loughner answered, his voice soft but audible.

Dressed in a tan prison jump suit, his hair grown out since his last court appearance, Loughner sat, showing little reaction, as Judge Burns heard a lengthy argument seeking public access to records in the case.

His lawyer Judy Clarke acknowledged the considerable time before Loughner's trial would begin.

"We are still months away from trial, your honor," said Clarke, whose past clients include the so-called Unabomber, jailed for life in 1998 after a 17-year campaign of parcel-bomb attacks which killed three.

Loughner was initially indicted in January on three counts of trying to kill US lawmaker Gabrielle Giffords and two of her aides in the shooting outside a supermarket, which also left a federal judge dead.

The new indictments, announced on Friday, include charges for the killing of nine-year-old Christina Taylor Green, the youngest victim, hailed as an inspiration by President Barack Obama in a memorial just days after the massacre.

In Wednesday's hearing Judge Larry Burns ruled to seal at least some of the court records, including search warrant records. Local media had requested the records be made public.

Previous hearings had been held in the state capital Phoenix. Arizona judges were disqualified from hearing the case, because of one of their colleagues was among those killed. Judge Burns is from California.